Fuel delivery device for stokers



Jan. 9, 1940.

H. C. CARTER FUEL DELIVERY DEVICE FOR S'I'OKERS Filed Aug. 3, 1936 //\//EN 72722 H. C. CARTER.

Patented Jan. 9, 1940 UNITED STATES PATENT OFFlCE Haskell 0. Carter, Portland,

Manufacturing Company, Port- Iron Fireman land, Oreg.

0rcg., assignor to Application August 3, 1936, Serial No. 94,078

1 Glaim.

' suspensionand the coarser particles are burned upon grates. The invention relates primarily to the classdescribed including an improved form of transfer housing and a means for crushing the coarser pieces and for limiting the size of the fuel delivered to the combustion chamber including a special means for pneumatically conveying such fuel.

The main object of this invention is the provision of an improved form of fuel delivery device for stokers of the spreader type which includes a means for reducing the lumps to dimensions below a maximum dimension and then delivering the sized fuel to the action of a pneumatic conveyor in a manner that foreign substances, such as metal or rock, may be removed from the passing fuel stream before it enters the combustion chamber.

The second object is to so unite the fueland air streams that the air will not only separate the :fuel from the foreign substances, such as tramp metal and stone, but also will serve to draw air in with the fuel due to an injector action which is set up thereby.

I accomplish these and other objects in the manner set forth in the following specification as illustrated in the accompanying drawing, in which:

Fig. 1 is a perspective view of the device showing its relation to a furnace, the front of which is partly broken away in section.

Fig. 2 is a fragmentary perspective view showing the fuel conveying pipe broken away and the door of the transfer housing open.

Fig. 3 is a vertical section taken approximately along the line 3--3 in Fig. 2.

Fig. 4 is a section elbows.

Similar numbers of reference refer to similar parts throughout the several views.

Referring in detail to the drawing, there is shown a hopper II] in which is The hopper I0 is placed directly over ahopper base I2 within whose trough shaped bottom [3 is disposed a fuel feeding worm which extends through an opening IS in the hopper base l2. Communicating with the opening I5 is a fuel duct It on whose upper side is preferably placed a clean out cover I! by means of which tramp material may be removed from the junction of the hopper base l2 and the fuel duct 16.

through one of the heated placed fuel I I.

The fuel feeding worm [4 extends through the fuel feeding duct l6 and it is desirable to taper the thickness of the flight portion l8 toward the end I9 of the duct H5. The core 20 of the worm 14 extends beyond the end l9 and has secured to 5 its end 2| an agitator vane 22. Surrounding the core 20 between adjacent portions of the worm I4 is a sizing and crushing worm 23. This is substantially at the junction of the members I! and I6.

Secured to the fuel feed duct I6 is a transfer housing 24 whose side 25 is substantially vertical and whose bottom 26 is horizontal as is its top side 21. At one side of the top side 21 is formed a semi-cylindrical cavity 28 hich is coaxial with 15 the worm core 20. The agitator vane 22 extends into the cavity 28 and is rotatable therein. The portion 29 of the housing 24, which forms the bottom of the cavity 28 extends toward the wall 25 but is spaced therefrom. 20

Underneath the portion 29 is formed an air inlet compartment 30 which communicates by means of the duct 3| with a fan (not shown) disposed within the casing 32. Air control devices 33 are provided for the duct 3| and their positions 25 are indicated although they will not be particularly described since they form no part of the present invention. A door 34 is hinged to the front of the housing 24 and provided with a latch 35 which is operable by a knob 36. 30

It is desirable to provide a gasket 31 against the inner side of the door 34 and also a striker plate 38 against which incoming fuel can be projected. Attached to the top side 21 and communicating with the interior of the housing 24 is a vertical 35 fuel feed pipe 39 on whose upper end is attached a heated elbow 40 which communicates by means of a horizontal fuel feed pipe 4| with a second steam heated elbow 42 from which extends the downturned fuel feed pipe 43 which communi- 40 cates with the steam heated elbow 44 from which the nozzle 45 extends horizontally through the furnace front 46 into the combustion chamber 41.

There is also indicated the position of the perforated grate 48 upon which the coarser particles 49 45 may be burned while the fines 50 are burned in suspension. Rotation is supplied to the worm M by means of a motor 5| through a transmission such as is now in common use and which is contained within the casing 52.

The operation of thedevice is as follows:

Assuming that a supply of fuel I l is placed with in the hopper Ill and that the worm I4 is rotated by'the motor 5| in response to its controls and that air is being delivered by the fan within the casing 32 to the duct 3 I, it follows that as the fuel II is carried by the worm I 4 throughthe opening I5, it must be first reduced to a size which will pass the worm 23 and that it will thereafter move freely along the fuel feed duct I6. When the fuel Ii enters the cavity 28 it is carried by the agitator 22 over the edge 53 of the portion 29 of the housing 24 where it is caught by the incoming air stream and carried upwardly through the pipe 39 and intermediate connections to the nozzle 45. 1

It will be noted that the first portion of travel is vertical and that any metal or stone which may be in the fuel will be too heavy to be carried upwardly past the elbow 40 but will fall down into the air inlet compartment 30, which is also a clean out box from which 'tramp metal 54 may be removed by merely opening the door 34.

It will be seen that the fuel having been first sized is then freed from its metallic and mineral foreign matter and is delivered pneumatically through the various connections to the nozzle 45 from which it is discharged into the combustion chamber 41.

By this construction all tendency to pack is eliminated especiallywhen wet, fine and dirty fuel is being fed. Also its feeding is uniform and positive which adapts this device especially to use in better type of stokers.

I claim:

A fuel delivery device having in combination a vertical pneumatic conveyor. a worm conveyor adapted to convey fuel horizontally into said pneumatic conveyor, a paddle on the end of said worm conveyor adapted to throw small quantities of fuel from said worm conveyor into said pneumatic conveyor, a metal collecting trap at the lower end of said pneumatic conveyor, means for delivering air to said metal trap and means for providing ready access to said trap, said trap and pneumatic conveyor affording a straight line, vertical passageway for air adapted to carry the fuel upwardly and to permit the metal to fall downwardly into said trap.

HASKE'LL C. CARTER. 

